Tortuosity of the innominate artery. Failure of retrograde catheterization of left side of heart by brachial arterial route.

Tortuosity of the innominate artery that does not produce a radiographic shadow was found to be a frequent obstacle to the passage of a catheter from the right brachial artery into the arch of the aorta and to the subsequent manipulation of the catheter into the left ventricle or coronary ostia. Prolonged attempts to negotiate the tortuous vessel resulted in nonfatal dissection and perforation of the innominate artery in two patients.